France's foreign minister announced Monday the "immediate" summoning of the US ambassador over a media report that the US spy agency eavesdropped on millions of phone calls made by French citizens.
"I have immediately summoned the US ambassador," French foreign minister Laurent Fabius told reporters as he arrived for an EU foreign ministers meeting in Luxemburg on Monday.
The allegations risked turning into a diplomatic row just as US Secretary of State John Kerry arrived in Paris for the start of a European tour over Syria, according to Reuters.
The US National Security Agency (NSA) monitored and taped some 70.3 million phone calls in France over a 30-day period between December 10 and January 8 this year, Le Monde reported in its online English edition, citing documents leaked from former NSA contractor Edward Snowden.
According to the paper, the NSA automatically picked up communications from certain phone numbers in France and recorded text messages. Le Monde said the documents gave grounds to believe that the NSA targeted not only people suspected of being involved in terrorism but also high-profile individuals from the world of business or politics.
US Ambassador to France Charles Rivkin declined immediate comment on reports that he had been called in by the French foreign ministry but stressed that US-French ties were close.
"This relationship on a military, intelligence, special forces ... level is the best it's been in a generation," Rivkin told Reuters as Kerry arrived in Paris.
The Le Monde article followed similar revelations by German weekly Der Spiegel that US agents had hacked into the e-mail account of former Mexican president Felipe Calderon.
Mexican authorities have said they will be seeking answers from US officials "as soon as possible" following the allegations.